Clamp circuits are used in certain applications to clamp an input or an output to a predetermined voltage level. For example, input of a sensor used in a disk drive application may need to be clamped to ground potential, when the sensor is not active. As circuit density and bandwidth requirements for many state of the art applications such as preamps for hard disk drives increase, fine line CMOS technology is used. To achieve the power, bandwidth and die size goals, the CMOS device dimensions are scaled down to sub micron dimensions. The voltage ratings of the devices are also scaled down. For example, in a 0.25 um CMOS technology, the devices typically are rated for voltages less than 3.6 Volts across the CMOS device gate and between drain-to-source.
As the voltage ratings of the devices are scaled down, there is a need to provide for clamp circuits that operate within the rated voltage. It is with these needs in mind, the current disclosure arises.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.